Pilot directing gyroscope



Sept. 1936. 'B' Q CARLSON ET AL l 2,652,866

PILOT DIRECTING GYROSCOE Filed Nov. 12, 19:62 :5 sheets-sheet 1rIM/LEIMTORS:J

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Sept. 1, 1936. B. G. CARLSON ET AL 2,052,855

` PILOT DIRECTING GYROSCOPE l Filed Nov. 12, 1932 asheets-sheet 2 l. INVNTORS:4

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Filed Npv'. 12, 195,2

INVENTORS':

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' l [ieri arZsw Patented sept'. 1, 1936 UNITED STATES i 2,052,866 lmrDIRECTING Gmoscorn Bert G. Carlson, Queens Village, N. Y., and Leslie 4F. Carter, Leonia, N. J., assi 1. Gyroscope Company, Inc.,

. corporation oi' New York gnors to Sperry Brooklyn, N. Y., a

Application November 12, 1932, Serial No. 642,360

4 Claims. (Cl. 33-204) This invention relates to directional gyroscopesfor aircraft which may or may not be used as a part of a pilot directingsystem. One object oi' the invention is to improve the construction ofthe locking or caging devices employed on such `gyroscopes so as toavoid damage to the gyroscope during the caging operation. Anotherobject is to provide a simple indicating means for showing the aviatorwhether or not the gyroscope is running at the proper speed so that theaviator may be warned not to use the instrument when it is not operatingproperly. Another object of the invention is to improve theaccuracy ofthe caging device so that when the gyroscope is released it will not bedisturbed by the releasv ingoperation and will remain in the setposition.

A further object of the invention is to provide a movable index on thegyroscope adapted to be controlled from a bomb sightor other point ofobservation so that the pilot may maintain the craft on' the coursedesired by the bomber by simply maintaining the reading of thedirectional gyroscope a constant.

Referring to the drawings showing one form our invention may assume,

Fig. 1 isa vertical section through the casing of one of our directionalgyroscopes.

Fig. 2 is a horizontal section of the same taken approximately on line2-2 of Fig. 1.

Fig. 3 is a plan view of the top of the lock or caging bar.

Fig. 4 is a face view of our directional gyroscope or pilot director.

Fig. 5 is a face view of a bomb sight showing the connection therefromto the pilot director, the former being drawn to a much smaller scalethan the latter.

Fig. 6 shows a modied form of bomb sight mounting in which the movementsof the bomb sight itself control the index on the pilot director.

Fig. 7 is a perspective view of the locking or caging bar of thegyroscope.

Figs. 8 and 9 are end views of the locking bar when engaging the frameof the gyroscope, Fig. 9

i showing the action of the gyroscope in depressing the bar when beingtested by the pilot.

Fig. 10 is a side elevation of the locking bar andl operating mechanismthereforv showing the bar in both the caging and uncaged positions.

Fig. 11 isa side elevation, partly in section, of the lower portion oi'the form ot bomb sight shown in Fig. -6. The gyroscope itself may be ofa form similar to that shown in the prior application of Bert G.

, such means Carlson, one of the joint inventors, Serial No. 608,189 forConstrained directional gyroscopes, led April 29, 1932, but it will beunderstood that our invention is applicable to other types. As v shown,the instrument comprises an outer cas- 5 lng or housing l for supportingand enclosing'the gyroscope, said housing being provided with a frontwindow 2 through which the indicator or compass card 3 on the gyroscopemay be read.

Within said casing there is journaled on vertical l0 bearings a verticalring 5, and within said ring there is supported on horizontal trunnions6, 6' a rotor bearing frame or ring l. 'Ihe rotor 8 is shown asjournaled for rotation 4within said ring on normally horizontal rotorbearings 9. rotor is preferably driven by an air jet or jets from anozzle or nozzles in tube IU, the streams of air striking pockets Il cutin the periphery of the rotor. Air may be supplied to the jets throughs.screened aperture located in the bottom plate i4 which carries the lowervertical bearing for the vertical ring 5 as shown in the said priorapplication, air being continuously Withdrawn from the casing throughpipe I5.

Such gyroscopes are usually provided with a setting means whereby theymay be set on any desired course or corrected from time to time by themagnetic compass. Our improved setting means lsshown as a thumb piecefixed to a short shaft 3l slidably and rotatably mounted in gland 32.Said shaft is provided with springpressed blocks 33 so that it may beyieldingly held either in its inner or outer positions by theirengagement in annular recesses 33. At its inner end said shaft isprovidedwith a crowned gear 34 which, when said shaft is pushed inwardlyas far as it will go, meshes with an annular spur gear 35 secured to.the baseoi' the vertical ring 5 whereby the gyroscope may be set byturning the knob 30.' Means are also provided to lock or centralize thegyroscope about its horizontal axis at this time to preventprecession.-'Preferably should operate before gears 3l and 35 arebrought into mesh and be kreleased after said gears are released toavoid damage to the gears and disturbance of the gyroscope. To thissleeve 43. Normally said sleeve rests in its lowerthe precessionalforces are-sufficient to most position but when shaft 3| is rst pushedinwardly, the pin 36 rotates the shaft 3S to raise the forked lever'40,thus raising sleeve 43 to the position shown in Figs. 1 and 10.

On top of said sleeve rests a. pin 45 preferably slidably mounted in alocking lever 46 pivoted at 41. Preferably said pin is yieldinglypressed downwardly by the spring 45 so that'the locking member 46 isresiliently supported on top of the sleeve 43. The outer end of lever 46is turned inwardly and upwardly to form a flattened seat 48, whichengages the flattened underside 1' of the rotor bearing ring 1 when thegyro is in the locked position. In prior constructions, the pin 45 wasrigidly mounted in the lever which gave rise to excessive torques attimes on the-gyra bearings during caging operation. Also, ithad been theprior practice to leave a slight gap between the caging arm and theco-acting surface 1' on the gimbal ring to overcome mechanicalinaccuracies in manufacture which caused the caging arm to bear tooheavily on the gimbal ring kat certain headings and not sufficiently onothers. It was, therefore, the prior practice to adjust the arm so thatthe surface 48 cleared the surface 1 on all headings a slight amountwith the attending loss of accuracy in caging. With the 'springconstruction, however, this play may beentirely eliminated, and at thesame time excessive torques on the bearings avoided because the springwill yield to permit slight precession under full pressure. The springis preferably designed with sufficient stiffnessI to completely overcomevthe gyro precession and restore the latter to horiwhen the setting knob30 is not being ro- A zontal tated but is designed to yield slightly incase full precessional forces 'are set up during turning of the knob 30.By using the spring also the gyroscope may be completely and accuratelypositioned on any heading so that when it is released the gyroscope willremain in the set position, whereas in the prior vsystem the gyro mightbe released with a slight inclination which would introduce error byreason of the torque set up by the erecting action ofthe spinning jetsas explained in the above referred to joint application.

The spring is also made stiff so that it will not yield when the knob 30is turned unless the gyroscope is up to the proper speed, in which casepress the locking foot 48 downwardlyas shown in Fig. 9.

v'Ihis phenomenon we make use of to furnish an indication to the scopeis operating properly so that he may be f be in the form of a foot 48and projecting forward therefrom so as warned not to rely on theinstrument unless it is rotating at proper speed. For instance,excessive cold sometimes causes the rotor bearings to stick due tounequal contraction of the parts, or ice or dirt may have clogged theVenturi tube used to exhaust the casing I. This indicator may flat strip56 secured to the to be visible through a slot 5I in the face or cover52` of the instrument. If the pilot desire to see whether the gyroscopeis operating properly, he merely pushes in the knob 30 and turns itslightly. If -the barl 5I disappears temporarily, he knows that theinstrument is operating, otherwise that it is not spinning at the properspeed or guide Y hgrizontal bearings are not free.

Around thetop of the vertical ring we mount the compass card aviator ofwhether the gyro- 3, which, in'this instance, is provided withgraduations both at the top and at the bottom. The bottom graduationsare designed to be read upon a stationary index 55 on the face, whilethe top graduations 54 are readable against an index 56 on a'ring;51rotatably mounted above the compass card 3. vSaid ring is shown asadjustable from a distance so that it may be set by the navigator orbomb sight operator in another part of the aircraft. As shown. said ringis secured to a worm gear 56 journaled in the bearing 59 at the top ofthe gyroscope and adjustable by means of a worm 60 mounted on the shaft6I. Said shaft is turned by bevel gear 62 thereon meshing with a bevelgear 63 on a shaft 64, said shaft being designed to be coupled to aflexible shaft 65 leading to the navigators compartment. As shown inFig. 5, the shaft leads to the bomb sight 66, the bomb sight operatorturning the handle 61 in one direction or the other as a change incourse is desired. All the pilot needv do, therefore, to keep on thedesired course is to bring the plane around so that a ,given indication,say zero, on the card 3 remains opposite the index 56 on ring 51. Incase the bomb sight is of the type disclosed in Fig. 11 of the jointapplication of E. W. Chafee and H. Murtagh, Serial No. 618,080 filedJune-18. 1932 for Bomb sights, turning a part of the bomb sight throughhandle 68 (Fig. 6) may b e made to turn directly the index 56 throughthe shaft 65. According to this construction, the outer binnacle ring 80has journalled thereon a ring or platform 16 which is turned on thebinnacle by means of the wormV 60 on shaft 6| from a handle 68. 'Ihisplatform, in Iturn, is provided with internal gear teeth 12 and on saidplatform is rotatably mounted an inner plate 8i which carries the opticsof the bomb sight. lSaid platform may be revolved' 4revolved by means ofworm 80', the platform 8i will likewise be revolved. When, however, the`part 16 alone is revolved, it rotates a shaft 83 by means of a pinion 84thereon meshing with an internal annulus 85, for the purpose of settingin the drift angle in the bomb sight. Turning of the bomb sight,therefore, from the handle 68 sets in the drift angle, but does not turnthe index 56 on the directional gyroscope. In approaching the target,the bomber first turns the sight through the handle 68, which does notturn shaft 65' but does turn the shaft 83 which sets in the proper driftangle as the sight is turned 'parallel to the ground course. As soon asthe straight ground track of the target is set up, the drift angle isestablished. He then brings the sight around to bear on the target bymeans of the handle 63, thus signalling the pilot to turn, but whichdoes not affect the properly set up drift angle. The pilot thencontinues' to use the directional gyroscope as his compass in apsome ofthese may be altered and others omittedwithout interfering with the moregeneral results outlined, and the invention extends to such use. 4

Having described our invention what we claim and desire to secure byLetters Patent is:

1. In a directional gyroscope having freedom about vertical andhorizontal axes, means for simultaneously locking the same about saidhorizontal axis and setting it about said vertical axis including amovable locking member adapted to A engage and centralize the gyroscopeabout its horizontal axis, means for setting the gyroscope while solocked about itsvertical axis, a spring means for supportingv saidlocking means adapted to permit temporary yielding thereof during asetting ,operation due to precession if the gyroscope is running, and anindicator secured to said locking member and viewable at the face of theinstrument for showing by its movement due to precession of thegyroscope/against said spring means when locked, whether the gyroscopeis spinning.

2. 'In a device of the character described, a casing, a gyroscope havinga vertical ring and mounted therein with three degrees of freedom forrelative movement about a vertical axis through a complete revolution,an annular gear carried by said ring, a pinion normally out ofengagement with said gear but operable axially into engage-l menttherewith, means for rotating said pinion to change the relationshipofsaid gyroscope'to said casing, a sleeve, means for raising said sleeveby axial movement of said pinion, a locking 1ever pivoted on said ringand having operative engagement with said sleeve for engaging andlocking the gyroscope about its horizontal axis, a yielding connectionbetween said lever and sleeve, whereby limited precessional movement ofsaid gyroscope is permitted when being reset, and an indicator securedto said locking member and viewable at the face of the instrument forshowing by its movement due to precession of the gyroscope against saidspring means when locked, whether the gyroscope is spinning.

3. In a directional gyroscope having freedom about vertical andhorizontal axes, means for simultaneously locking the same about saidhorizontal axis and setting itv about said vertical axis including amovable locking member adapted to engage and centralize the gyroscopeabout its horizontal axis, means for setting the gyroscope while solocked about its vertical axis, a compass card-mounted on and rotatablein azimuth with said gyroscope, a xedindex on which said card isnormally read, a movable index also readable on said card, and meansoperable from a distance for setting said movable index to show thedesired course changes.

4. In apilot directing system for bombing aircraft, the combination witha bomb sight and directional gyroscope, of means for turning the bombsight in azimuth for setting up the drift angle, separate means forturning the sight on the target after said drift angle has been set up,a movable index on said gyroscope, and means operable by the turning ofsaid sight from the second of said means only for shifting said indexthrough a corresponding angle.

BERT G. CARLSON. LESLIE E. CARTER.-

